POS1056 PREDICTORS OF RISK OF ANTI-TNF TREATMENT WITHDRAWAL IN PATIENTS WITH PSORIATIC ARTHRITIS – DATA FROM MOSCOW UNIFIED ARTHRITIS REGISTRY (MUAR)
Authors: K. Lytkina, E. Koltsova, E. Shmidt, G. Lukina, E. Zhilyaev
Journal: Annals of the Rheumatic Diseases (2022)

Background Retention on therapy is the most important integrative indicator of the success of the drug, reflecting both the effectiveness and tolerability and general acceptability of treatment. This indicator can be evaluated with high accuracy in observational trials. Objectives to identify predictors of TNF inhibitors withdrawal risk in patients with PSA. Methods Patients with (PSA) from Moscow Unified Arthritis Registry (MUAR) treated with TNF inhibitors were analyzed. All treatment episodes interrupted due to non-medical reasons were excluded from the study. Breaks in biologic therapy up to 4 months were allowed (for infliximab a break in therapy up to 6 month was considered possible) The search for predictors of treatment withdrawal risk was carried out in two steps. At the first step possible predictors of the risk of TNF inhibitors therapy discontinuation were selected in univariate сorrelations. At the second step significant predictors of retention on TNF inhibitors therapy were selected by forward stepwise variable selection within multivariate Cox regression. The relationship between the line of anti-TNF treatment and the risk of therapy discontinuation was analyzed separately. Results We analyzed 371 treatment episodes in 239 patients with PSA enrolled in MUAR, 97 male (40.6%), 50.2±12.1 years old. The age of disease onset was 36.8 ± 12.7 years. The patients received adalimumab (ADA) (101 treatment episodes), golimumab (GOL) (n=32), infliximab (INF) (n=55), certolizumab pegol (CER) (n=31), etanercept (ETA) (n=152). There were 187 (50.4%) completed treatment episodes. The relationship between risk of TNF inhibitors discontinuation and the drug line was analyzed. We found that the withdrawal risk on the second TNF inhibitor didn’t significantly differ from the withdrawal risk on the first line anti-TNF drug (p=0,201). The third and subsequent lines of TNF inhibitors where associated with the significantly higher risk of withdrawal. Direct step-by-step selection of variables made possible to identify the following significant predictors of retention on therapy – social status, the presence of HLA B-27, fever during the disease, pain in sacral zone at the onset of the disease, coccidinia during the disease, patient reports on the association of the onset of the disease with a genital infection (uretritis, adnexitis, prostatitis, endometritis) (Table 1) Table 1. Independent predictors of anti-TNF treatment discontinuation Predictors Direction of association with the dicontinuitation risk p Social status Working patients had a lower risk 0.038 The presence of HLA-B27 HLA-B27 positive patients had lower risk 0.005 Temperature elevation during the disease Patients WHO reported an increase in body temperature during the disease had an increased risk &lt; 0.001 Sacral pain at the onset of the disease Patients who reported sacral pain at the onset of the disease had an increased risk 0.037 Coccygeal pain during the disease Patients who reported pain in the coccyx during the disease had an increased risk 0.026 Presence of genital infections Patients who reported a link between the onset of the disease and a history of urethritis or endometritis had a high risk 0.011 After adjusting for the line of therapy and the identified predictors of the risk of drug withdrawal it was found that retention on all analyzed TNF inhibitors in patients with PSA didn’t differ significantly (Figure 1) Conclusion The identified significant mutually independent predictors of the risk of discontinuation of treatment may be useful when choosing biological therapy in patients with PSA. Discontinuation therapy risk of various TNF inhibitors does not differ significant. The risk of withdrawal therapy with the second TNF inhibitor is not significantly differ from the first one. Thus, in case of failure of the first attempt of treatment with an TNF inhibitor, a second attempt can be made The probability of success of subsequent attempts seems to be very low Figure 1. Adjusted analysis of treatment survival on TNF inhibitors Disclosure of Interests None declared